Critical speed of screw drives

Influences on the critical speed

The permissible speed of a trapezoidal or ball screw drive is restricted by the maximum permissible speed of the threaded nut (theoretical upper limit) and the critical speed of the trapezoidal or ball screw spindle. The critical speed of the threaded spindle is dependent on the type of bearing arrangement, the nominal diameter, the support spacing between the support bearings and the number of spindle supports. The critical speed is also influenced by the direction of load on the locating bearings and the tensile or compressive load.

The critical speeds of the trapezoidal or ball screw drive as a function of the actuator length are given in the relevant descriptive chapters. The size and type of the bearing arrangement are already taken into consideration, while the influence of the load direction must be taken into consideration.